Which hand cleaning material is most effective in removing bacteria?
Introduction/Hypothesis
Michael's hypothesis: The soap having a higher percentage of alcohol will help clean hands the best.
Will's hypothesis: The soap that is the most expensive will clean hands the best.
Annotated bibliography for background information
Johnson, T D. "Washing Your Hands Can Be the Key to Good Health." American Public Health Association 39.7 (2009): 15. Web.
Widmer, A F. "Replace Hand Washing with the Use of a Waterless Alcohol Hand Rub?" Clinical Infectious Diseases 31(2000): 136-143. Web.
Materials list
1 digital thermometer
1 tub Clorox Wipes
1 bottle Dawn dish soap
1 bottle Softsoap
1 bottle GermX hand sanitizer
1 bottle Bath and Body works hand soap
4 petri dishes
bacteria source
Procedure
1. Before testing each type of soap, wipe hands with Clorox wipe for a clean start
2. Pet the bacteria source (dog)
3. Wash hands with 1/2 tbs of soft soap and water with a temp of 108.3
4. Swipe right index finger into the labeled petri dish
5. Repeat these steps using the remaining 3 soap brands
Variables and Controls
Independent Variables are the various types of soap: Softsoap, Dawn, GermX, and Bath and Body Works. Dependent Variable is the level of bacteria that grows as a result of using each type of soap. Controls: Amount of soap, water temperature, using same finger each time for sample.
Data recordings and pictures
Bacteria Source
1/2 tbs of soap
Swiping a sample
Day 6 - starting to see some variations in samples.
Cleanest sample so far
Dirtiest sample so far.
Charts and graphs
Bacteria Growth Chart
Soft Soap
Dawn
Bath and Body Works
GermX
Day One
No change
No change
No change
No change
Day Two
No change
No change
No change
No change
Day Three
1 large spot, 10 small spots
No change
4 large spots
1 large spot, 1 small spot
Day Four
1 large spot, 10 small spots
No change
6 large spots
1 large spot, 3 small spots
Day Five
Multiple spots in petri dish
No change
6 large spots
1 large spot, 3 small spots
Day Six
Same
Same
Same
Same
Day Seven
Same
Same
Same
Same
Day Eight
More spots than day 5
Same
Growing more spots
Same
Day Nine
Spots and white flecks of growth
Some slight discoloration – not concentrated in a spot like the others
Covered in spots and white flecks of growth similar to that of the Soft Soap
No new spots
Day Ten
Even more of the white flecks
No change since yesterday
More white flecks and spots
No new spots
Conclusions
After ten days of observation on the sample petri dishes, it was determined that Dawn dish soap had the least amount of bacteria. This nullifies Michael’s hypothesis that the soap with the greatest amount of alcohol (GermX) would result in the least amount of bacteria. It also nullifies Will’s hypothesis that the most expensive soap (Bath and Body Works) would result in the least amount of bacteria.
photos of display board:
Sources of Error
As controlled as we can try to be, every step of the procedure is not going to be exactly identical. Outcomes might be different based on hygiene condition of dog before sampling, bacteria in the water (tap water vs. spring water), use of cleansing agent before each sample. These could also possibly affect outcomes.
Which hand cleaning material is most effective in removing bacteria?
Introduction/Hypothesis
Michael's hypothesis: The soap having a higher percentage of alcohol will help clean hands the best.Will's hypothesis: The soap that is the most expensive will clean hands the best.
Annotated bibliography for background information
Johnson, T D. "Washing Your Hands Can Be the Key to Good Health." American Public Health Association 39.7 (2009): 15. Web.Widmer, A F. "Replace Hand Washing with the Use of a Waterless Alcohol Hand Rub?" Clinical Infectious Diseases 31(2000): 136-143. Web.
Materials list
1 digital thermometer1 tub Clorox Wipes
1 bottle Dawn dish soap
1 bottle Softsoap
1 bottle GermX hand sanitizer
1 bottle Bath and Body works hand soap
4 petri dishes
bacteria source
Procedure
1. Before testing each type of soap, wipe hands with Clorox wipe for a clean start2. Pet the bacteria source (dog)
3. Wash hands with 1/2 tbs of soft soap and water with a temp of 108.3
4. Swipe right index finger into the labeled petri dish
5. Repeat these steps using the remaining 3 soap brands
Variables and Controls
Independent Variables are the various types of soap: Softsoap, Dawn, GermX, and Bath and Body Works. Dependent Variable is the level of bacteria that grows as a result of using each type of soap. Controls: Amount of soap, water temperature, using same finger each time for sample.Data recordings and pictures
Charts and graphs
Bacteria Growth Chart
Conclusions
After ten days of observation on the sample petri dishes, it was determined that Dawn dish soap had the least amount of bacteria. This nullifies Michael’s hypothesis that the soap with the greatest amount of alcohol (GermX) would result in the least amount of bacteria. It also nullifies Will’s hypothesis that the most expensive soap (Bath and Body Works) would result in the least amount of bacteria.
photos of display board:
Sources of Error
As controlled as we can try to be, every step of the procedure is not going to be exactly identical. Outcomes might be different based on hygiene condition of dog before sampling, bacteria in the water (tap water vs. spring water), use of cleansing agent before each sample. These could also possibly affect outcomes.